ESTES PARK, CO, USA
N83809
Piper PA-34-220T
The pilot filed an IFR flight plan and made a night departure from Erie, Colorado, en route to Boise, Idaho. After receiving his IFR clearance in flight, he requested a VFR-on-top clearance and 'a vector heading for (Rock Springs, Wyoming)...just to verify...a radar vector heading just to check that...I'm having a little heading problems here, but switching to compass nav, but we're VFR on top. In fact, it's pretty much VFR below us now.' Nine minutes later, radar contact with the airplane was lost. The airplane remained missing for about a month, and the wreckage was not recovered from a mountain side for 7 months. Radar data indicated the airplane descended from an encoded altitude of 15,100 feet to 13,900 feet in 1 minute, 31 seconds, or about 800 feet per minute. No distress call was received. Wreckage examination failed to explain why the airplane descended or anything causal to accident.
HISTORY OF FLIGHT On January 31, 1996, at 2155 mountain standard time, a Piper PA-34-220T, N83809, registered to and operated by Rocky Mountain Propellers, Inc., was destroyed when it collided with mountainous terrain during descent 8 miles northwest of Estes Park, Colorado. The airline transport pilot was fatally injured. Visual meteorological conditions prevailed, and an IFR flight was filed for the personal flight conducted under Title 14 CFR Part 91. The flight originated from Erie, Colorado, approximately 2115. According to a family member, the pilot was en route to Payne Field, Everett, Washington, to fulfill his U.S. Army Reserve duty. A spokesman for the airplane owner said the pilot telephoned the morning of the accident and asked that the airplane be put in a heated hangar. At 1910, the pilot telephoned the Denver Automated Flight Service Station and received a standard weather briefing that included pertinent NOTAMs (Notice to Airmen), forecast weather, and a VNR (VFR flight not recommended) statement. He then filed an IFR (instrument flight rules) flight plan, and indicated the route of flight would be from Erie, Colorado, direct to Laramie and Rock Springs, Wyoming, then direct to Boise, Idaho, where he was to stop for fuel. The proposed departure time was 2030. The initial cruising altitude was to be 12,000 feet and the true airspeed was given as 160 knots. A resident adjacent to the airport said he observed a twin engine airplane take off about 2130. It circled the airport twice before disappearing from view. He said it was quite cold and there was snow and ice on the ground. The pilot contacted Denver TRACON (Terminal Radar Approach Control) at 2120 and said he was VFR over the Tri-County Airport and requested his IFR clearance to Boise. The airplane was identified on radar at 2125 when it was 5 miles northeast of the Jefferson County Airport, and the pilot was instructed to climb and maintain 12,000 feet and to fly a heading of 010 degrees. The pilot was issued his IFR clearance at 2126 and was instructed to contact Denver Departure Control. Upon doing so, the pilot was told to fly a heading of 360 degrees to join the Laramie transition and to resume his own navigation. At 2135, the pilot requested and was cleared to maintain VFR on top. The pilot advised he was proceeding direct to Rock Springs adding, "It's VFR below now, just come scattered..." Indicating he would fly at 14,500 feet, he requested a "vector heading for (Rock Springs) just to verify..." He was instructed to contact the Denver Air Route Traffic Control Center (ARTCC) with his request. The pilot contacted Denver Center at 2136 and asked, "Could you give me a radar vector heading just to check that...We're going up to fourteen five but if need be, we'll climb to higher to get over the Divide there." The sector controller advised that he "had marginal radar coverage out there at that altitude...You're going to need a little more altitude...before you make that turn." After consulting the next sector, the controller advised the pilot, "I'm showing...uncorrected for wind from your present position about a two eighty two for direct Rock Springs Vortac and...be something on the order of about two seventy five, something between two seventy and two seventy five." At 2141, the pilot contacted the next sector controller and was given the current Denver altimeter setting. At 2148, when asked if he was proceeding direct to Rock Springs, the pilot replied, "That's affirm. I'm having a little heading problems here, but switching to the compass nav, but we're VFR on top. In fact, it's pretty much VFR below us now." At 2157, the controller advised the pilot radar contact had been lost. There was no reply. The controller contacted other aircraft (Vanguard 113, ABEX 383, Amflight 555, and Evergreen 364) and asked that they try contacting N83809. No contact was made and they reported no ELT (emergency locator transmitter) signal on frequency 121.5 MHz. A search for the missing airplane was initiated on February 1. The Civil Air Patrol coordinated the aerial search and the National Park Service coordinated the ground search. Also participating in the search were military and privately chartered aircraft. The search was suspended on February 13, 1996. On March 3, 1996, two members of the Rocky Mountain Search and Rescue ski patrol sighted the wreckage, located on the northeast couloir of 13,514-foot Ypsilon Mountain, at the 13,164-foot level. Climbers from the National Park Service reached the accident site on March 9, 1996, and removed a small amount of human remains for DNA testing. Since a 15 foot snow cornice was above the accident site and conditions were not safe to conduct an on-scene investigation, it was decided to postpone all activities until spring or summer. On July 17, 1996, a second expedition to the accident site was accomplished by National Park Service climbers. Approximately 30 pounds of human remains were recovered. The wreckage was eventually recovered by helicopter on August 5, 1996. METEOROLOGICAL INFORMATION According to the U.S. Naval Observatory in Washington, D.C., sunset was at 1716 and civil twilight ended at 1745 on the day of the accident. The moon rose at 1412 that afternoon and set on February 1 at 0452. It was described as "waxing gibbous," moving from a first quarter to a full moon. Its surface was 87% illuminated, and was located 67 degrees above the horizon and 71 degrees south of true east. The isogonic line nearest the accident site is 11.5 degrees east. WRECKAGE AND IMPACT INFORMATION The wreckage rested on a 45 degree slope and on a magnetic heading approximately 270 degrees. Terrain slope adjacent to the wreckage averaged 60 degrees and in some places, the slope was 90 degrees. The wings, empennage, and cockpit were inverted. The wreckage was removed from the accident site and transported to Beegles Aircraft Service in Greeley, Colorado, where they were examined on August 12-14. All major components of the airplane, with the exception of one propeller blade, were recovered. All flight controls (stabilator, rudder, trim tabs, ailerons, and flaps) remained attached to their respective structures. The stabilator trim drum was 1-3/8 inch extended, exposing 12 threads. The rudder trim tab was deflected 7/8-inch to the left and the trim drum was 1-1/4 inch extended. According to the Piper Aircraft Corporation representative, this equates to near-neutral and about 65% nose right positions. During the recovery operation, the tail section was inadvertently dropped from the helicopter but later retrieved. Both wings exhibited extensive frontal impact damage. Both fuel selector valves were open. Wing spar separations were consistent with overload failure. Both engines were completely fragmented. The left engine mixture and fuel controller were in the midpoint position. Both magnetos, although extensively damaged, produced spark at all leads when rotated. The left turbocharger bore rotational scoring marks. There were rub marks on the right turbocharger turbine wheel blades. Both pressure relief valves moved freely and appeared functional. The three blades from the right propeller assembly bore gouges and 90 degree scratch marks on their cambered surfaces. One blade was missing 8 inches of its tip. The two blades from the left propeller assembly bore similar but more extensive damage. The engine controls (throttles, propeller controls, and mixtures) were in the full forward position. The left and right oil pressure gauge needles were in the mid (green) and high (yellow) range. The left and right needles on the tachometer registered 2,700 and 2,450 rpm, respectively. The other engine gauges were destroyed. The outside air temperature was jammed at -40 degrees F. The oxygen control handle was off. The pilot's seat belt was found fastened. Although the shoulder harness was not attached to the seat belt, both the seat belt and shoulder harness exhibited evidence tension overload failure. MEDICAL AND PATHOLOGICAL INFORMATION A gross examination of the remains (autopsy report #96CA-032) was conducted by Dr. Patrick C. Allen of the Larimer County Coroner's Office. In addition, a forensic analysis of homogenized muscle tissue revealed no presence of drugs. TESTS AND RESEARCH The wreckage was located by utilizing CDR List 3 radar data from both the Denver Terminal Radar Control and Air Route Traffic Control Center. The data was electronically transmitted to a California Civil Air Patrol member's computer equipped with a Radar Viewpoint program. According to this data, the airplane leveled off at an encoded altitude of 15,000 at 2139:59. For the next 14 minutes, ground speed averaged 160 knots and altitude varied only +200 feet. At 2153:53, the airplane began a descent from an encoded altitude of 15,100 feet that continued until radar contact was lost at 2155:24, or 1 minute, 31 seconds. At that time, the airplane was at an encoded altitude of 13,900 feet, a difference of 1,200 feet. The rate of descent varied between 545 and 2,400 feet per minute, but averaged 800 feet per minute. The last radar fix was 40 degrees, 27'22"N and 105 degrees, 40'17"W. The wreckage was located at a GPS (Global Positioning System) position of 40 degrees, 27'28"N and 105 degrees, 40'43"W. ADDITIONAL INFORMATION According to his wife, the pilot awoke at 0800 on the morning of the accident and arrived at his office approximately 1000. He was in a deposition from 1300 until 1730. The wreckage was released to the owner's representative on August 14, 1996. Parties to the investigation included the Federal Aviation Administration, Piper Aircraft Corporation, Teledyne Continental Motors, and Allied Signal.
Descent into mountainous terrain for reasons undetermined.
Source: NTSB Aviation Accident Database
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